Assessing motivational biases in brain and behavior: Event-related potential and response time concomitants of the approach-avoidance task

The approach-avoidance task (AAT) is designed to measure implicit motivated action biases instantiated by emotional stimuli and alterations in such biases that drive psychiatric disorder. While some research has measured AAT event-related potential (ERP) correlates to establish bias sensitivity even at a neural level, a lack of work with unpleasant, pleasant, and neutral stimuli together and a common focus on psychiatric disorder-matched (rather than generally emotional) content limits conclusions that can be drawn. Thus, current work extends the AAT literature by testing ERP modulations across normatively unpleasant, pleasant, and neutral conditions; and supporting the task's use as an individual difference assessment, it also provides data on AAT reliability and initially explores anxiety-related effects when stimuli are not disorder-matched. In 38 participants including 19 anxiety treatment-seeking individuals, 32 sensor electroencephalography revealed robust N100, N200, and late positive potential (LPP) ERP components and bias-consistent modulations for unpleasant images (reduced N200s on unpleasant push relative to pull trials; enhanced LPP for unpleasant compared to neutral trials). Meanwhile, modulations were less consistent with emotion-driven bias for other conditions-that is, LPPs were enhanced but N200 was not modulated for pleasant images, and for neutral images, N200 was unexpectedly enhanced on push compared to pull trials. Following these analyses, reliability tests revealed excellent raw ERP reliabilities but lower reliabilities for modulation scores, and comparing treatment- to non-treatment-seeking groups showed no preliminary indication of ERP modulation changes when stimuli are not personally relevant. How these findings together inform understanding of AAT as a measure of bias is discussed. Our research tests foundational assumptions of an approach-avoidance task (AAT) used to assess-and, increasingly, modify-psychiatric disorder-relevant approach/avoidance biases. We provide further evidence for a neurobehavioral avoidance bias in unpleasant AAT conditions and for overall reliability of electrocortical and behavioral AAT indices, while also identifying other critical factors (stimulus intensity and complexity) to consider when designing AAT studies and interpreting effects. This work could improve the precision with which AAT is used to assess individual approach/avoidance biases and modify these in bias modification work.